From 4a823c0be80fa996234ebb41c80d40458b1bec1e Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Fri, 26 Jan 2018 16:48:49 +0800 Subject: opp: cpu: Replace GFP_ATOMIC with GFP_KERNEL in dev_pm_opp_init_cpufreq_table After checking all possible call chains to dev_pm_opp_init_cpufreq_table() here, my tool finds that this function is never called in atomic context, namely never in an interrupt handler or holding a spinlock. And dev_pm_opp_init_cpufreq_table() calls dev_pm_opp_get_opp_count(), which calls mutex_lock that can sleep. It indicates that atmtcp_v_send() can call functions which may sleep. Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai Signed-off-by: Viresh Kumar --- drivers/opp/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/opp/cpu.c b/drivers/opp/cpu.c index 2d87bc1adf38..0c0910709435 100644 --- a/drivers/opp/cpu.c +++ b/drivers/opp/cpu.c @@ -55,7 +55,7 @@ int dev_pm_opp_init_cpufreq_table(struct device *dev, if (max_opps <= 0) return max_opps ? max_opps : -ENODATA; - freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC); + freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL); if (!freq_table) return -ENOMEM; -- cgit v1.2.3 From b6d8ef86cb7b8b6920b6815ebf1352757d3adb87 Mon Sep 17 00:00:00 2001 From: Aishwarya Pant Date: Wed, 7 Feb 2018 19:04:36 +0530 Subject: Documentation/ABI: update cpuidle sysfs documentation Update cpuidle documentation using git logs and existing documentation in Documentation/cpuidle/sysfs.txt. This might be useful for scripting and tracking changes in the ABI. Signed-off-by: Aishwarya Pant Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-devices-system-cpu | 77 +++++++++++++++++++++- 1 file changed, 75 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index bfd29bc8d37a..4ed63b6cfb15 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -108,6 +108,8 @@ Description: CPU topology files that describe a logical CPU's relationship What: /sys/devices/system/cpu/cpuidle/current_driver /sys/devices/system/cpu/cpuidle/current_governer_ro + /sys/devices/system/cpu/cpuidle/available_governors + /sys/devices/system/cpu/cpuidle/current_governor Date: September 2007 Contact: Linux kernel mailing list Description: Discover cpuidle policy and mechanism @@ -119,13 +121,84 @@ Description: Discover cpuidle policy and mechanism Idle policy (governor) is differentiated from idle mechanism (driver) - current_driver: displays current idle mechanism + current_driver: (RO) displays current idle mechanism - current_governor_ro: displays current idle policy + current_governor_ro: (RO) displays current idle policy + + With the cpuidle_sysfs_switch boot option enabled (meant for + developer testing), the following three attributes are visible + instead: + + current_driver: same as described above + + available_governors: (RO) displays a space separated list of + available governors + + current_governor: (RW) displays current idle policy. Users can + switch the governor at runtime by writing to this file. See files in Documentation/cpuidle/ for more information. +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/name + /sys/devices/system/cpu/cpuX/cpuidle/stateN/latency + /sys/devices/system/cpu/cpuX/cpuidle/stateN/power + /sys/devices/system/cpu/cpuX/cpuidle/stateN/time + /sys/devices/system/cpu/cpuX/cpuidle/stateN/usage +Date: September 2007 +KernelVersion: v2.6.24 +Contact: Linux power management list +Description: + The directory /sys/devices/system/cpu/cpuX/cpuidle contains per + logical CPU specific cpuidle information for each online cpu X. + The processor idle states which are available for use have the + following attributes: + + name: (RO) Name of the idle state (string). + + latency: (RO) The latency to exit out of this idle state (in + microseconds). + + power: (RO) The power consumed while in this idle state (in + milliwatts). + + time: (RO) The total time spent in this idle state (in microseconds). + + usage: (RO) Number of times this state was entered (a count). + + +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/desc +Date: February 2008 +KernelVersion: v2.6.25 +Contact: Linux power management list +Description: + (RO) A small description about the idle state (string). + + +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/disable +Date: March 2012 +KernelVersion: v3.10 +Contact: Linux power management list +Description: + (RW) Option to disable this idle state (bool). The behavior and + the effect of the disable variable depends on the implementation + of a particular governor. In the ladder governor, for example, + it is not coherent, i.e. if one is disabling a light state, then + all deeper states are disabled as well, but the disable variable + does not reflect it. Likewise, if one enables a deep state but a + lighter state still is disabled, then this has no effect. + + +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency +Date: March 2014 +KernelVersion: v3.15 +Contact: Linux power management list +Description: + (RO) Display the target residency i.e. the minimum amount of + time (in microseconds) this cpu should spend in this idle state + to make the transition worth the effort. + + What: /sys/devices/system/cpu/cpu#/cpufreq/* Date: pre-git history Contact: linux-pm@vger.kernel.org -- cgit v1.2.3 From 69728051f5bf15efaf6edfbcfe1b5a49a2437918 Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Fri, 9 Feb 2018 08:11:26 -0800 Subject: PM / wakeirq: Fix unbalanced IRQ enable for wakeirq If a device is runtime PM suspended when we enter suspend and has a dedicated wake IRQ, we can get the following warning: WARNING: CPU: 0 PID: 108 at kernel/irq/manage.c:526 enable_irq+0x40/0x94 [ 102.087860] Unbalanced enable for IRQ 147 ... (enable_irq) from [] (dev_pm_arm_wake_irq+0x4c/0x60) (dev_pm_arm_wake_irq) from [] (device_wakeup_arm_wake_irqs+0x58/0x9c) (device_wakeup_arm_wake_irqs) from [] (dpm_suspend_noirq+0x10/0x48) (dpm_suspend_noirq) from [] (suspend_devices_and_enter+0x30c/0xf14) (suspend_devices_and_enter) from [] (enter_state+0xad4/0xbd8) (enter_state) from [] (pm_suspend+0x38/0x98) (pm_suspend) from [] (state_store+0x68/0xc8) This is because the dedicated wake IRQ for the device may have been already enabled earlier by dev_pm_enable_wake_irq_check(). Fix the issue by checking for runtime PM suspended status. This issue can be easily reproduced by setting serial console log level to zero, letting the serial console idle, and suspend the system from an ssh terminal. On resume, dmesg will have the warning above. The reason why I have not run into this issue earlier has been that I typically run my PM test cases from on a serial console instead over ssh. Fixes: c84345597558 (PM / wakeirq: Enable dedicated wakeirq for suspend) Signed-off-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki --- drivers/base/power/wakeirq.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c index a8ac86e4d79e..6637fc319269 100644 --- a/drivers/base/power/wakeirq.c +++ b/drivers/base/power/wakeirq.c @@ -321,7 +321,8 @@ void dev_pm_arm_wake_irq(struct wake_irq *wirq) return; if (device_may_wakeup(wirq->dev)) { - if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED) + if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && + !pm_runtime_status_suspended(wirq->dev)) enable_irq(wirq->irq); enable_irq_wake(wirq->irq); @@ -343,7 +344,8 @@ void dev_pm_disarm_wake_irq(struct wake_irq *wirq) if (device_may_wakeup(wirq->dev)) { disable_irq_wake(wirq->irq); - if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED) + if (wirq->status & WAKE_IRQ_DEDICATED_ALLOCATED && + !pm_runtime_status_suspended(wirq->dev)) disable_irq_nosync(wirq->irq); } } -- cgit v1.2.3 From 433986c2c265d106d6a8e88006e0131fefc92b7b Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Sat, 10 Feb 2018 19:13:58 +0100 Subject: PM / runtime: Update links_count also if !CONFIG_SRCU Commit baa8809f6097 (PM / runtime: Optimize the use of device links) added an invocation of pm_runtime_drop_link() to __device_link_del(). However there are two variants of that function, one for CONFIG_SRCU and another for !CONFIG_SRCU, and the commit only modified the former. Fixes: baa8809f6097 (PM / runtime: Optimize the use of device links) Cc: v4.10+ # v4.10+ Signed-off-by: Lukas Wunner Signed-off-by: Rafael J. Wysocki --- drivers/base/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index b2261f92f2f1..5847364f25d9 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -310,6 +310,9 @@ static void __device_link_del(struct device_link *link) dev_info(link->consumer, "Dropping the link to %s\n", dev_name(link->supplier)); + if (link->flags & DL_FLAG_PM_RUNTIME) + pm_runtime_drop_link(link->consumer); + list_del(&link->s_node); list_del(&link->c_node); device_link_free(link); -- cgit v1.2.3 From d7212cfb05ba802bea4dd6c90d61cfe6366ea224 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 12 Feb 2018 11:34:22 +0100 Subject: PM: cpuidle: Fix cpuidle_poll_state_init() prototype Commit f85942207516 (x86: PM: Make APM idle driver initialize polling state) made apm_init() call cpuidle_poll_state_init(), but that only is defined for CONFIG_CPU_IDLE set, so make the empty stub of it available for CONFIG_CPU_IDLE unset too to fix the resulting build issue. Fixes: f85942207516 (x86: PM: Make APM idle driver initialize polling state) Cc: 4.14+ # 4.14+ Signed-off-by: Rafael J. Wysocki --- include/linux/cpuidle.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 8f7788d23b57..a6989e02d0a0 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -225,7 +225,7 @@ static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, } #endif -#ifdef CONFIG_ARCH_HAS_CPU_RELAX +#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_ARCH_HAS_CPU_RELAX) void cpuidle_poll_state_init(struct cpuidle_driver *drv); #else static inline void cpuidle_poll_state_init(struct cpuidle_driver *drv) {} -- cgit v1.2.3